WASHINGTON —
Ukrainian Prime Minister Arseniy Yatsenyuk is meeting with President Barack Obama Wednesday, days before a referendum in Crimea where a Russian-speaking majority is likely to bring the strategic peninsula under Moscow's control. Analysts say the meeting will not stop the referendum, which is set for Sunday, but warn of the urgency of stopping Russia from moving on to other Russian-populated regions of the former Soviet Union.

Russia has made it clear that a flurry of diplomatic activity ahead of the Sunday referendum will have little effect on its plans to take control of the Crimean region. Washington-based political analyst Peter Eltsov said that no matter what official name it will assume, Crimea is lost to Ukraine. He added Ukraine has to fight to prevent any Russian attempt to move further.

"It's the biggest fear of the new Ukrainian government and it is quite likely - depending of course on the political situation - that [Russian President Vladimir] Putin will try to go to certain parts of eastern Ukraine. We need to remember that there is no direct by-land connection between Russia and the Crimean peninsula," said Eltsov.

Stephen Blank, an analyst with the American Foreign Policy Council, agreed. He also placed blame on the European Union for a lax response to Russia's move to take over the strategic peninsula.

"There have been no real organized economic sanctions on Russia; there have been no systematic strategic military actions to strengthen Ukraine’s ability to defend itself; and if I were Mr. Putin I would think I’ve gotten away with it. I don’t think he will in the end, but I think up till now there has been too little action, and whatever action there has been, has been uncoordinated," said Blank.

Yatsenyuk's visit to Washington has another significant purpose; Eltsov said the interim government in Kyiv needs U.S. economic support to survive, and the political support to block Moscow from advancing further into Ukraine's territory. Eltsov added that for now, Russian-speaking populations in eastern Ukraine seem to reject Russian intervention, but that the mood can quickly change.

"The identity really is a fluid category, as anthropolgists say. It depends on the situation, in particular in case of war like we saw, for example, in the former Yugoslavia. Those issues can really change and switch between sides really fast - overnight - depending on rumors, depending on particular political developments. This is a very dangerous situation," said Eltsov.

Eltsov also said Putin seems intent on reviving some of the former Russian Empire as his legacy, and if he is not stopped, he will attempt to bring back under Moscow's control other Russian-populated areas, for example in Kazakhstan.

"It is not impossible that given the political situation he would want to take a chunk of northern Kazakhstan, which is populated mostly by Russians. But that would be, of course, a much more difficult enterprise," said Eltsov.

Eltsov said the best guarantee against Russian aggression is a NATO presence in vulnerable areas. He thinks Russia is not likely to invade NATO members Latvia, Lithuania and Estonia, despite their sizeable Russian-speaking populations.

"The country which is not militarily allied and has a very weak military of its own, and is in such financial chaos, is definitely a very easy target," said Eltsov.

Last week, the U.S. government authorized sanctions, including visa restrictions, against those found to have violated Ukraine's territorial integrity. The European Union also took measures against Russia, suspending talks on visas and a new economic agreement.